The present invention relates to workstations for industrial or commercial use. Workstations of this nature may be used in the electronic industries for assembling components or products, or in light manufacturing industries for assembling a wide range of mechanical products, as well as in other applications. More particularly, the present invention relates to improvements in the main frame (or xe2x80x9ctable framexe2x80x9d) for such workstations.
Workstations for use in manufacturing industries have long been known. Such workstations generally include left and right side upright structures called xe2x80x9clegsxe2x80x9d which are mounted on wheeled feet or bases for support and mobility and which may be adjusted in height to set the table top of the workstation at a desired height. The legs are connected together at their upper ends by a rear frame member called a fixing frame, and toward the user""s position or xe2x80x9cfrontxe2x80x9d of the workstation, struts are carried by the top of the adjustable leg structures for supporting the tabletop or work surface on which the manufacturing or assembly are performed. The front edge of the table or support surface is supported by a stringer which is mounted at its sides respectively to the forward portions of the table top support struts.
As used herein, the xe2x80x9cleftxe2x80x9d and xe2x80x9crightxe2x80x9d sides of a workstation are the left and right sides respectively from the standpoint of a worker at the workstation. The xe2x80x9cfrontxe2x80x9dof the workstation is adjacent to the worker, and the xe2x80x9cbackxe2x80x9d of the workstation is remote from the worker when located in the normal working position.
It is desirable in workstations of this nature that the table top be adjustable in height. This is accomplished, in some cases, through the upright leg structures. However, the use of adjustable legs of the type used in the past have been accompanied by undesirable instability in the support legs, particularly at the higher elevations of adjustment. That is, as the prior art legs are extended for higher height adjustment, the portions of the legs which overlap becomes reduced, thereby reducing the ability of the extended leg to resist lateral forces, particularly forces in a fore and aft direction.
Some workstations have height adjusting mechanisms which are motor driven, and therefore more expensive. Others are manually adjustable as by hand crank, and therefore somewhat less expensive, and finally, some are completely manually adjustable (called xe2x80x9cslide legxe2x80x9d adjusting mechanisms), which is the least expensive. In the past, providing the three different types of height adjustments has required the use of substantially different components and sub-assemblies in the adjustable leg structures of each type, thus adding costs for manufacturers desiring to offer all three versions to customers.
Moreover, the fixing frame, which is a structural support member that spans the distances between the tops of the legs, provides lateral support to the frame and load support for material or tools placed on or supported by the work surface. The fixing frame is an important structural component of the table frame since it supports any accessories or storage racks mounted to the table frame.
The adjustable leg of the present invention is symmetrical about a vertical transverse plane (i.e., extending side to side) so that the same structure may be a left or a right side leg. This is referred to as being xe2x80x9cunhandedxe2x80x9dxe2x80x94that is, being neither right-handed nor left-handed.
The leg assembly includes inner and outer legs which are received in sliding telescoping relation. The inner and outer legs each have a side panel and two end walls (front and rear) which are V-shaped when viewed from above. A pair of slide assemblies are incorporated into each leg assembly. The slide assemblies are laterally aligned in the fore-to-aft direction. The V-shaped end walls and the slide assemblies act to stabilize the main frame in the fore-to-aft direction; and the fixing frame stabilizes the main frame laterally and supports the load. The adjustable leg assembly of the present invention is adapted for a slide leg (manual) adjustment or it may be upgraded to a hand crank or to a motorized version using the same basic structure.
The shape of the improved fixing frame of the present invention is a box beam with upper and lower channels. The box beam is formed by fixing (as by welding) a large channel member to the vertical web of a formed metal main beam. The channels are open and extend horizontally and they are parallel to one another. The box beam adds structural support to carry vertical load, and the open channels serve as mounting tracks for upright supports, if desired. Access ports are provided in one side of the box beam for use as a chase or open duct for storage and routing of electrical cables and pneumatic hoses suppling electricity and pneumatic pressure to the workstation. The web of the main beam of the fixing frame is solid and acts as a modesty panel. In summary, the fixing frame acts as a slotted track for mounting components, a modesty panel and wire/hose duct.
Other features and advantages of the present invention will be apparent to person skilled in the art from the following detailed description of an illustrated embodiment accompanying by the attached drawing wherein identical reference numerals will refer to like parts in the various use.